1. Technical Field
The present invention relates generally to the field of semiconductor processing, and more particularly, to a method of forming an inductor above the last metal wiring level, and the structure so formed.
2. Related Art
Conventionally inductors are fabricated within metal wiring levels of a semiconductor device. This type of fabrication requires at least two levels of thick conductive wire and two levels of vias, necessitating the use of at least four masking steps. As a result, conventional inductor fabrication creates high production costs. In addition, conventional inductor fabrication produces inductors that tend to have high parasitic capacitance due to the close proximity of the inductor to the substrate. Finally, the large physical dimensions (height/width) needed to increase inductor quality factor can be incompatible with standard small dimension on chip wires and vias.
Therefore, there is a need in the industry for a method of forming an inductor that solves these and other problems.